JPWO2009122931A1 - Personal authentication method and personal authentication device using subcutaneous blood flow measurement - Google Patents

Abstract

The laser beam is expanded to irradiate the finger pad, and the light reflected from the subcutaneous blood vessel layer is imaged as a laser speckle on the image sensor using an optical system. An amount representing the speed of change is calculated, a finger blood flow map is obtained using the numerical value as a two-dimensional map, and the blood flow map is compared with collated personal data. In a personal authentication method using subcutaneous blood flow measurement, a personal authentication method including imaging a laser speckle on an image sensor using an area shifted from a laser irradiation region as an observation area of the image sensor, and a method used therefor Personal authentication device. An improved technique for accurately extracting a fingerprint pattern or the like is provided for a method and apparatus for performing personal authentication using a fingerprint pattern or the like based on laser speckles on the finger pad.

Description

The present invention relates to a personal authentication method characterized by measuring subcutaneous blood flow and a device used therefor. In particular, the present invention relates to a method for extracting a pattern corresponding to a fingerprint from a blood flow map of the finger pad and authenticating the user and a device used therefor.

Various systems that use a laser or the like and input a pattern as an image and analyze it have been developed to date instead of the visual method that has been used for fingerprint authentication. Many methods have been proposed for the sensor part to detect fingerprints, combining the difference in scattering angle between peaks and valleys with the total reflection condition, an optical method to capture the fingerprint pattern directly into the image sensor, and the difference in charge distribution on the contact surface. A method for extracting a pattern by using a semiconductor sensor for detecting the above has been put into practical use. In addition, a method of extracting a fingertip or palm vein pattern using near-infrared light and performing personal authentication has been proposed, and commercialization is also progressing (for example, see Patent Documents 1 to 3). Since the fingerprint pattern is more complicated than the vein pattern, it may be possible to construct a more accurate personal authentication system. However, if the fingerprint is made of a material such as silicon, the same shape as the finger pad is forged. There is a risk of incorrect authentication.

On the other hand, when the laser is irradiated toward the living body, the intensity distribution of the reflected scattered light forms a dynamic laser speckle (random spot pattern) by moving scattering particles such as blood cells, and this pattern is reflected on the image plane. It is known that the blood flow distribution of capillaries in the vicinity of the living body surface can be imaged by detecting with an image sensor, quantifying the temporal change of the pattern in each pixel, and displaying it in a map. And several techniques and apparatuses which measure the blood flow map under the skin and the fundus oculi by using such a phenomenon have been proposed by the present inventors (for example, see Patent Documents 4 to 9).

The present inventor has completed the invention of using the blood flow map shown in the above-mentioned document for personal authentication by combining it with a fingerprint pattern, and has already proposed (see Patent Documents 10 and 11).
In these patent documents, when the blood flow of the fingertip is imaged by the laser blood flow imaging method, the blood flow in the valley portion of the fingerprint is faster than the mountain portion, so that the fingerprint pattern appears in the blood flow map. Is used to authenticate that the finger is alive (Patent Document 10). In addition, by using near-infrared laser light, the blood flow distribution inside the finger is detected, and the accuracy of identity authentication and the exclusion of others is increased, or the blood flow at the fingertip fluctuates in synchronization with the heartbeat, There has also been proposed a method for determining whether the finger is a living finger or a simulated finger by analyzing the waveform (Patent Document 11).

However, even with these methods, for example, if a very thin silicon film imitating fingerprint irregularities is attached to the finger surface, the sensor will pick up the blood flow of the finger behind and live There is a problem of judging that it is. Further, in winter when the room temperature is lowered, the fingertip becomes cold, the blood flow on the surface is lowered, and the pulsation component cannot be detected, so that it is judged as a simulated finger. As far as the inventor is aware, no method or apparatus for overcoming these weaknesses has been proposed yet.

JP-A-5-73666 Japanese Patent Laid-Open No. 8-16752 JP 2003-331268 A Japanese Patent Publication No. 5-28133 Japanese Patent Publication No. 5-28134 JP-A-4-242628 JP-A-8-112262 JP 2003-164431 A JP 2003-180641 A International Publication No. 05/122896 Pamphlet International Publication No. 07/097129 Pamphlet

For personal authentication methods and devices that use fingerprint patterns based on laser speckles on the finger pad, take a fingerprint mold, create a sheet with irregularities resembling fingerprints using a material such as silicon, and paste it on the fingertip There is a risk of false authentication by a finger as a biometric fingerprint. Further, in winter when the room temperature decreases, there is a problem that the fingertip becomes cold, the blood flow on the surface is lowered, the pulsation component cannot be detected, and the finger is judged as a simulated finger. The present invention is intended to provide a highly accurate personal authentication method and authentication apparatus that solve these problems.

In order to recognize that it is a living finger, it is necessary to accurately detect that there is a blood flow fluctuation synchronized with the heartbeat. For this purpose, the present inventor has found that it is only necessary to perform blood flow measurement with weight on the internal blood flow change rather than the skin surface layer portion, and in order to realize this, the following technical matters are created. It is a thing. (1) If the laser irradiation site and the region observed by the image sensor are shifted, the optical signal component detected after passing through the inside rather than the surface layer increases. (2) If the laser is passed through the finger for a sufficiently long distance by irradiating the finger pad with laser and installing the image sensor on the fingertip side or vice versa, Capable of accurately capturing blood flow fluctuations. (3) When a film with high scattering properties and no blood flow is pasted on the finger surface, a fixed pattern is superimposed on the pattern formed on the image sensor due to interference of laser scattered waves, and the dispersion value between pixels Will increase. It is possible to determine whether the finger is a simulated finger by using a difference in dispersion values between pixels.

The object of the present invention is achieved by the following present invention described in claims 1 to 14 based on the technical knowledge of the inventor.

According to the first aspect of the present invention, the laser beam is spread to irradiate the finger pad, and the light reflected from the blood vessel layer under the skin is bound as a laser speckle on the image sensor using an optical system. And calculating an amount representing the speed of temporal change in the amount of light received at each pixel of the laser speckle, converting the numerical value into a two-dimensional map to obtain a blood flow map of the finger pad, In a personal authentication method using subcutaneous blood flow measurement, which is characterized by comparing and collating with pre-registered personal data, a laser beam on the image sensor is set as an observation area of the image sensor. This is a personal authentication method using subcutaneous blood flow measurement, characterized in that speckle is imaged.

The invention described in claim 2 uses a laser beam as a linear spot, uses a line sensor as an image sensor, and sets the observation area of the line sensor and the linear spot to be parallel to each other. The personal authentication method using subcutaneous blood flow measurement according to claim 1.

The invention described in claim 3 irradiates the center part of the finger pad with laser, and sets the observation region of the image sensor on the fingertip side of the finger pad. This is the personal authentication method used.

The invention described in claim 4 irradiates the fingertip part of the finger pad with a laser, and sets the observation region of the image sensor in the center part of the finger pad. This is the personal authentication method used.

According to a fifth aspect of the present invention, a signal waveform representing the intensity distribution of the amount of received light in each pixel for at least one column on the image sensor is detected, and the signal waveform is set as a signal waveform of a biological finger set in advance. 5. The personal authentication method using subcutaneous blood flow measurement according to claim 1, further comprising a function of detecting a simulated finger in comparison.

The invention described in claim 6 is one or two irradiating means for expanding the laser beam to irradiate the finger pad, and receiving light that has a number of pixels and receives reflected light from the blood vessel layer under the finger pad. Means, storage means for storing the output of each pixel obtained by the light receiving means, and calculation means for calculating an amount representing the speed of temporal change of the amount of received light in each pixel from the stored contents of the storage means , Second storage means for storing a two-dimensional distribution of the calculation results obtained in each pixel as a blood flow map, and blood flow map stored in the second storage means for pre-registered personal data In the personal authentication apparatus provided with the means for comparing / determining, the irradiating means and the light receiving means are arranged so that the laser irradiation part and the observation area of the reflected light by the image sensor are shifted. Use subcutaneous blood flow measurement It is the personal authentication device.

According to the seventh aspect of the present invention, a signal waveform representing the intensity distribution of the amount of received light in each pixel of at least one column on the image sensor is detected, and the signal waveform is set as a signal waveform of a biological finger set in advance. 7. The personal authentication device using subcutaneous blood flow measurement according to claim 6, further comprising means for detecting a simulated finger.

According to the eighth aspect of the present invention, a laser beam is spread to irradiate the finger pad, and light reflected from a subcutaneous blood vessel layer is imaged as a laser speckle on an image sensor using an optical system. An amount representing the speed of temporal change in the amount of light received at each pixel of the speckle is calculated, the numerical value is converted into a two-dimensional map to obtain a blood flow map of the finger pad, and the blood flow map is registered in advance. Subcutaneous blood flow measurement, characterized by comparing and checking the average blood flow over time or within a certain area and comparing / determining the obtained value with a predetermined standard. In the personal authentication method used, an individual using subcutaneous blood flow measurement, in which laser speckles are imaged on the image sensor, using the region shifted from the laser irradiation site as the observation region of the image sensor It is a testament method.

The invention described in claim 9 includes one or two irradiating means for expanding the laser beam to irradiate the finger pad, and light reception for receiving reflected light from a blood vessel layer under the finger pad having a large number of pixels. Means, storage means for storing the output of each pixel obtained by the light receiving means, and calculation means for calculating an amount representing the speed of temporal change of the amount of received light in each pixel from the stored contents of the storage means , Second storage means for storing a two-dimensional distribution of the calculation results obtained in each pixel as a blood flow map, and blood flow map stored in the second storage means for pre-registered personal data In a personal authentication device comprising means for comparing / determining the average blood flow over time or in a certain region and comparing / determining the obtained value with a predetermined reference , The irradiation means and the light receiving means, It is the personal authentication device using subcutaneous blood flow measurement, characterized in that observation area of the light reflected by the irradiated part and the image sensor of the Za are arranged to be shifted.

According to the tenth aspect of the present invention, a signal waveform representing the intensity distribution of the amount of received light in each pixel of at least one column on the image sensor is detected, and the signal waveform is set as a signal waveform of a biological finger set in advance. The personal authentication device using subcutaneous blood flow measurement according to claim 9, further comprising means for detecting a simulated finger.

According to an eleventh aspect of the present invention, a laser beam is spread to irradiate the finger pad, and light reflected from a subcutaneous blood vessel layer is imaged as a laser speckle on an image sensor by using an optical system. An amount representing the speed of temporal change in the amount of light received at each pixel of the speckle is calculated, the numerical value is converted into a two-dimensional map to obtain a blood flow map of the finger pad, and the blood flow map is registered in advance. In the personal authentication method using subcutaneous blood flow measurement, characterized by comparing and collating with existing personal data, using at least one column on the image sensor using the time zone before, after or during these operations A subcutaneous waveform characterized by adding a function of detecting a simulated finger by detecting a signal waveform representing the intensity distribution of the amount of received light in each pixel and comparing the signal waveform with a signal waveform of a biological finger set in advance. Blood flow measurement Is the use the personal authentication method.

The invention described in claim 12 has one or two irradiating means for expanding the laser beam and irradiating the finger pad, and receiving light that has a large number of pixels and receives reflected light from the blood vessel layer under the finger pad. Means, storage means for storing the output of each pixel obtained by the light receiving means, and calculation means for calculating an amount representing the speed of temporal change of the amount of received light in each pixel from the stored contents of the storage means , Second storage means for storing a two-dimensional distribution of the calculation results obtained in each pixel as a blood flow map, and blood flow map stored in the second storage means for pre-registered personal data In the personal authentication device provided with a means for comparing / determining, a signal waveform representing the intensity distribution of the amount of received light in each pixel for at least one column on the image sensor is detected, and the signal waveform is set in advance to a predetermined finger of a living body. Compared to the signal waveform of擬指 a personal authentication device using subcutaneous blood flow measurement, characterized in that the addition means for detecting.

According to a thirteenth aspect of the present invention, a laser beam is spread to irradiate the finger pad, and light reflected from a subcutaneous blood vessel layer is imaged as a laser speckle on an image sensor using an optical system. An amount representing the speed of temporal change in the amount of light received at each pixel of the speckle is calculated, and a blood flow map of the finger pad is obtained using the numerical value as a two-dimensional map, and the blood flow map is stored in advance as personal data. In the personal authentication method using subcutaneous blood flow measurement characterized by comparing and collating with the laser, a laser beam is passed through a shielding plate having a number of horizontally long slits, thereby forming a lattice-like laser spot on the finger pad. Project the spot and the direction of the scanning line of the sensor and analyze the data on the spot to detect a blood flow map of the surface layer of the finger pad and its change over time, or A personal authentication method utilizing subcutaneous blood flow measurements and detecting the blood flow map and its change with time of the inner layer portion of the data to analyze the finger pad between the pot.

According to a fourteenth aspect of the present invention, a laser beam is spread to irradiate the finger pad, and light reflected from a subcutaneous blood vessel layer is imaged as a laser speckle on an image sensor using an optical system. An amount representing the speed of temporal change in the amount of light received at each pixel of the speckle is calculated, and a blood flow map of the finger pad is obtained using the numerical value as a two-dimensional map, and the blood flow map is stored in advance as personal data. An individual using subcutaneous blood flow measurement, which compares and collates with the average, calculates the time course of the average blood flow in the whole or in a certain area, and compares and determines the obtained value with a predetermined standard In the authentication method, a laser beam is passed through a shielding plate having a large number of horizontally long slits to project a lattice-like laser spot on the finger pad, and the direction of the scanning line of the sensor is aligned with the spot. Analyzing the data on the spot and detecting the blood flow map of the surface of the finger pad and its change over time, or analyzing the data between the spots and the blood flow map of the inner layer of the finger pad and its It is a personal authentication method using subcutaneous blood flow measurement characterized by detecting a change with time.

Personal authentication technology that uses fingerprint patterns based on laser speckles on the finger pad draws a fingerprint pattern using blood flow information unique to the living body, and the pattern is temporally synchronized with the heartbeat. This model uses fluctuations, and it is very difficult to forge a model that combines a two-dimensional pattern and a time axis. However, there is still a defect that a simulated finger imitating the fingerprint unevenness with silicon resin or the like, or a thin sheet of the finger stuck to the finger is mistakenly recognized as a real finger. According to the method and apparatus of the present invention, blood flow information inside the finger can be extracted more accurately, and even when the blood flow is low due to cold in a cold region, the internal blood flow signal can be reliably obtained. Since it can be picked up, a clear distinction can be made between a simulated finger and a standard human finger.

The conceptual diagram of the personal authentication technique based on the conventional laser speckle is shown. The conceptual diagram of the personal authentication technique based on the laser speckle of this invention is shown. It is a figure which shows an example of the relationship between the irradiation spot of the laser in this invention, and the observation position of an image sensor. It is a figure which shows the other example of the relationship between the irradiation spot of the laser in this invention, and the observation position of an image sensor. It is a figure which shows the signal of the line sensor obtained from the blood vessel layer and stratum corneum of a finger | toe subcutaneously. It is a figure which shows the example in the case of projecting a grid | lattice-like laser spot on the finger pad which is the other aspect of this invention.

Among biometric information, information obtained from blood flow has a feature that it cannot be authenticated unless the sensor is operated while the person is alive. Personal authentication technology using fingerprint patterns based on laser speckles on the finger pad measures blood flow spatially modulated by fingerprint irregularities by blood flow measurement technology using laser scattering. In order to measure subcutaneous blood flow, first, the laser beam is expanded and applied to the finger pad, and the light reflected from the subcutaneous blood vessel layer is imaged as a speckle pattern on the image sensor using an optical system. . Then, the speckle is continuously scanned using the image sensor, and the light reception integrated by the amount representing the speed of time change of the light reception amount in each pixel, for example, the average time change rate or the exposure time of the image sensor. The reciprocal of the amount of fluctuation is calculated, and the obtained numerical value is converted into a two-dimensional map to obtain a finger blood flow map. Next, a fingerprint pattern or the like appearing as a blood flow map is compared / determined with personal data registered in advance. And in another aspect, in addition to the above process, the process of calculating | requiring the time-dependent change of the average blood flow in the whole or a certain area | region and comparing and determining with a predetermined reference | standard is also added. These may include a step of displaying the obtained blood flow map or fingerprint pattern, or a means for displaying as necessary.

The present invention is a further improvement of the personal authentication technology using a fingerprint pattern or the like based on the laser speckle of the finger pad described above, and an area shifted from the laser irradiation area is an observation area of reflected light by an image sensor. As a personal authentication method or an apparatus used therefor, the method includes imaging laser speckles on an image sensor.

FIG. 1 shows a conceptual diagram of a personal authentication technique using a conventional fingerprint pattern based on laser speckle based on finger blood flow measurement. 1 is a small laser light source such as a semiconductor laser, 2 is an optical system, 3 is a finger pad, 4 is a laser spot (irradiation spot) or observation region, 5 is an imaging optical system, 6 is an image sensor or CCD camera, 7 is An analysis personal computer 8 is a display.

As shown in FIG. 1, light emitted from a small laser light source 1 such as a semiconductor laser is spread through an optical system 2 to irradiate a wide area (irradiation spot 4) of the finger pad 3. This irradiation spot is imaged on a light receiving surface such as an image sensor or a CCD camera 6 through the imaging optical system 5. A video signal obtained from an image sensor or a CCD camera is A / D converted and taken into the personal computer 7 for analysis, and an amount representing the speed of temporal change in received light amount at each pixel, for example, an average time change rate or an image. The reciprocal of the variation in the amount of received light integrated according to the exposure time of the sensor is calculated, and if necessary, displayed on the display 8 in a map form to obtain blood flow map data.

Since the blood flow map of the capillaries under the finger pad expressed in this way shows a fingerprint pattern or the like, this data is compared with previously registered data for personal authentication. As a method / means for comparing / determining a fingerprint pattern, etc. appearing as a blood flow map with pre-registered personal data, it is not necessary to use a special method / means. it can.

By the way, in the conventional method and apparatus shown in FIG. 1, since the laser spot and the observation field of view coincide with each other, the camera from the skin surface layer portion is used rather than the light returning to the surface after diffusing to the deep skin of the finger. The ratio of the light scattered toward the image sensor 6 is higher than that detected by the image sensor 6. For this reason, there is a problem that blood flow fluctuations in the skin are difficult to detect efficiently.

FIG. 2 shows a conceptual diagram in which laser speckles are imaged on the image sensor by shifting the laser irradiation site and the observation field of the reflected light from the image sensor. In FIG. 2, 1 is a semiconductor laser, 2 is an optical system, 9 is a laser spot, 10 is a linear observation region, 11 is an imaging lens, and 12 is a line sensor. In FIG. 2, the laser spot is a horizontally long ellipse, but may be a linear spot. Further, the observation region does not need to be linear, and the sensor may be a two-dimensional image sensor. Preferred is a case where the laser beam is used as a linear spot and a line sensor is used as an image sensor so that the observation area of the line sensor and the linear spot are parallel to each other.

As shown in FIG. 2, when the irradiation spot 9 of the laser and the observation position 10 of the image sensor are shifted, for example, as shown in FIG. It will return to the observation position 14. In this case, data depending on the blood flow inside the tissue is obtained, and blood flow fluctuations synchronized with the heartbeat can be clearly observed even when the fingertip is cold.

Or, for example, as shown in FIG. 4, when the center part of the finger pad is irradiated with a laser and the sensor is brought to the tip of the finger, the light from the laser spot 13 propagates in the skin over a long distance. The received wavefront is received at the observation position 14, and the blood flow waveform is further stabilized. In FIG. 4, it is also possible to irradiate the fingertip part of the finger pad with laser and set the observation area of the image sensor in the center part of the finger pad.

Furthermore, in the present invention, a signal waveform representing the intensity distribution of the amount of received light in each pixel for at least one column on the image sensor is detected, and this signal waveform is compared with a preset signal waveform of a biological finger. It is also a preferred aspect to add a function of detecting a simulated finger. This will be described with reference to FIG. In FIG. 5, 15 is a subcutaneous blood vessel layer, 16 is a stratum corneum, and 17 is a thin film such as silicon.

FIG. 5 (a) is a line sensor signal obtained from the subcutaneous blood vessel layer 15 and stratum corneum 16 of a normal finger. The horizontal axis P of the graph is the pixel position (pixel), and the vertical axis I is the optical signal intensity. Show. FIG. 5B is a signal obtained when a thin film 17 such as silicon is applied to the surface of the finger, and the waveform contrast is high as can be seen from the graph. In general, when a laser hits a layer without blood flow, that is, a layer in which scattering particles do not move, a stationary speckle is formed when reflected scattered light interferes with the image plane. Therefore, when the light intensity distribution is scanned with a line sensor or the like, a signal waveform with high contrast is obtained as shown in the graph of FIG. 5B, and the pattern is stationary, so the waveform does not change.

However, when many blood cells are moving inside, the interference condition changes every moment on the image plane (because it interferes in the same phase in some cases and in the opposite phase in other cases), the pattern of light and dark changes over time. To go. Actually, since the pattern changes rapidly up to several kilohertz, it is integrated within the exposure time of the image sensor, resulting in a blurred image, and the contrast is lowered as shown in the graph of FIG. When a tissue without blood flow is pasted on the finger surface, a stationary speckle image is obtained because scattered particles that do not move are in front, and a scanning signal with high contrast is obtained as shown in the graph of FIG. 5B. It is done. By utilizing this effect, for example, a certain reference value that can be taken by a living body can be determined, and an artifact that deviates therefrom can be determined.

5, that is, a signal waveform representing the intensity distribution of the amount of received light in each pixel for at least one column on the image sensor is detected, and this signal waveform is compared with a preset signal waveform of a finger of a living body. Thus, the function of detecting a simulated finger can be used in addition to the invention described in claims 1 to 4 of the present invention. However, such a mode may be directly combined with a conventional personal authentication method using subcutaneous blood flow measurement. That is, in the conventional personal authentication method, a signal waveform representing the intensity distribution of the received light amount in each pixel for at least one column on the image sensor is obtained by using time zones before or after each operation for authentication. A function of detecting a simulated finger can be added and combined by detecting and comparing the signal waveform with a preset biological finger signal waveform. This allows a clearer distinction between simulated fingers and standard human fingers.

In the above description of the present invention, an example using a line sensor has been mainly described. However, in another aspect of the present invention, a two-dimensional image sensor such as a TV camera can be used as in the related art. In particular, as shown in FIG. 6, a lattice-like laser spot 19 may be projected on the finger pad by passing a laser through a shielding plate 18 having a large number of horizontally long slits. In this case, the blood flow distribution in the surface layer and its change with time can be detected by matching the direction of the horizontally long spot and the scanning line of the camera and analyzing the data on the spot. Or if the data between spots are analyzed, an internal blood flow distribution and its temporal change can be investigated. These data can be used for very precise personal authentication by comparing / collating with pre-registered personal data or comparing / determining with a predetermined standard. In such a case, when a fingerprint image based on blood flow is captured, the shielding plate 18 is not inserted, and the shielding plate 18 is inserted only when the internal blood flow distribution is captured.

In the present invention, the laser beam is expanded to irradiate the finger pad, and the light reflected from the subcutaneous blood vessel layer is imaged as a laser speckle on the image sensor using an optical system. An amount representing the speed of temporal change in the amount of received light is calculated, the numerical value is converted into a two-dimensional map to obtain a blood flow map of the finger pad, and the blood flow map is compared with pre-registered personal data. Conventional techniques characterized by collation include irradiating the finger pad with a single laser beam of a specific wavelength, or irradiating the finger pad with a plurality of different laser beams of a specific wavelength simultaneously or sequentially. It also includes a method / means for obtaining a superimposed or plural blood flow velocity map for the reflected light from the blood vessel layer in the tissue.

Lasers have different tissue penetration characteristics depending on the wavelength. When the wavelength is short, such as visible light, only the blood flow distribution close to the surface, that is, the fingerprint pattern is obtained, but the wavelength is long, such as near infrared light. Since the object goes deep inside the tissue, a blood flow map reflecting the internal blood flow distribution can be obtained. Since there are individual differences in the internal blood flow distribution and it is difficult to counterfeit, if this is added to the authentication data, the personal verification accuracy can be improved by a synergistic effect. The present invention can also be applied to such prior art. At this time, for example, using a near-infrared laser beam that can reach the internal tissue of the finger pad and a visible laser beam that is easily absorbed by the subcutaneous stratum corneum, a blood flow map of the finger pad that is obtained by each reflected light is obtained. When two types of blood flow maps are obtained simultaneously or sequentially, the laser irradiation spot and the observation area may be shifted.

According to the present invention, there is provided an apparatus for executing the personal authentication method as described above. The apparatus of the present invention includes one or two irradiating means for expanding the laser beam to irradiate the finger pad, a light receiving means for receiving reflected light from a blood vessel layer under the finger pad having a large number of pixels, Storage means for storing the output of each pixel obtained by the light receiving means, calculation means for calculating an amount representing the speed of temporal change in the amount of received light in each pixel from the stored contents of the storage means, and each pixel The second storage means for storing the two-dimensional distribution of the calculation result obtained in step 2 as a blood flow map, and comparing / determining the blood flow map stored in the second storage means with pre-registered personal data In the personal authentication apparatus provided with the means for performing subcutaneous blood flow measurement, wherein the irradiation means and the light receiving means are arranged so that the laser irradiation site and the observation field of the reflected light by the image sensor are shifted from each other Personal recognition using It is a device.

Another apparatus of the present invention receives one or two irradiation means for expanding the laser beam to irradiate the finger pad and a reflected light from a blood vessel layer under the finger pad having a large number of pixels. A light receiving means, a storage means for storing the output of each pixel obtained by the light receiving means, and a calculation means for calculating an amount representing a time change rate of the received light amount in each pixel from the stored contents of the storage means. And a second storage means for storing the two-dimensional distribution of the calculation results obtained in each pixel as a blood flow map, and a blood flow map stored in the second storage means, In addition to the means for comparing / determining with the data, in addition to these, a personal authentication apparatus having means for calculating the change over time of the average blood flow in the whole or in a certain region and comparing / determining with a predetermined standard In the above, the irradiation means and the light receiving And the step is a personal authentication device using subcutaneous blood flow measurement, characterized in that it is arranged so that fields of view of the light reflected by the irradiated part and the image sensor of the laser deviates.

In the personal authentication device of the present invention, in addition to the above means, a signal waveform representing the intensity distribution of the amount of received light in each pixel for at least one column on the image sensor is detected, and the signal waveform is preset. A means for detecting a simulated finger can be added as compared with the signal waveform of a biological finger.

Still another aspect of the device of the present invention is to receive one or two irradiation means for expanding the laser beam to irradiate the finger pad and the reflected light from the blood vessel layer under the finger pad having a large number of pixels. A light receiving means, a storage means for storing the output of each pixel obtained by the light receiving means, and a calculation means for calculating an amount representing a time change rate of the received light amount in each pixel from the stored contents of the storage means. And a second storage means for storing the two-dimensional distribution of the calculation results obtained in each pixel as a blood flow map, and a blood flow map stored in the second storage means, In a personal authentication device comprising means for comparing / determining with data, a signal waveform representing the intensity distribution of the amount of received light in each pixel for at least one column on the image sensor is detected, and the signal waveform is set to a predetermined biological Compared to the finger signal waveform,擬指 a personal authentication device using subcutaneous blood flow measurement, characterized in that the addition means for detecting.

As the irradiation means, for example, light emitted from a semiconductor laser is expanded through a lens, and a wide area of the finger pad is irradiated at once. An image sensor such as a line sensor or an area sensor is used as the light receiving means. The electrical signal from the sensor is A / D converted and then stored in a storage unit of a microcomputer or a personal computer. The image signal is continuously taken into the storage unit for several seconds, the difference between two consecutive images is obtained by a program set in advance in a microcomputer or a personal computer, and the speed of temporal change in the amount of received light is calculated. Or, when the light amount changes rapidly within the image sensor exposure rate, that is, within the exposure time of the image sensor, the signal is integrated, and conversely, the speed of light reception amount change over time is calculated. To do. The calculation result can be displayed as a two-dimensional color map on a personal computer screen according to the arrangement of each pixel. Various conventionally known means can be used as means for comparing / determining the calculated value or the fingerprint pattern displayed on the display means with a personal fingerprint pattern registered in advance. Further, a change over time of the blood flow value averaged for a region having a finger pad over several seconds is obtained, and for example, the wave shape, amplitude, period, etc. of the blood flow change can be used.

The personal authentication method and apparatus according to the present invention is difficult to counterfeit because it combines a complex fingerprint pattern and biometric information. Taking advantage of this advantage, it can be used for entrance / exit monitoring and immigration control of facilities that require advanced security management.

Claims (14)

The laser beam is spread to irradiate the finger pad, and the light reflected from the subcutaneous blood vessel layer is imaged as a laser speckle on the image sensor using an optical system, and the amount of light received by each pixel of the laser speckle An amount representing the speed of change is calculated, the numerical value is converted into a two-dimensional map, a blood flow map of the finger pad is obtained, and the blood flow map is compared with collated personal data. In the personal authentication method using the characteristic subcutaneous blood flow measurement, the laser blood flow is characterized in that laser speckle is imaged on the image sensor using the region shifted from the laser irradiation region as the observation region of the image sensor. Personal authentication method using measurement. 2. The subcutaneous blood according to claim 1, wherein a laser beam is used as a linear spot, a line sensor is used as an image sensor, and the observation area of the line sensor and the linear spot are set parallel to each other. Personal authentication method using flow measurement. The personal authentication method using subcutaneous blood flow measurement according to claim 1, wherein a laser is irradiated to a central portion of the finger pad, and an observation area of the image sensor is set on the fingertip side of the finger pad. 2. The personal authentication method using subcutaneous blood flow measurement according to claim 1, wherein the fingertip portion of the finger pad is irradiated with a laser, and an observation region of the image sensor is set in the center portion of the finger pad. A function for detecting a simulated finger by detecting a signal waveform representing the intensity distribution of the amount of received light in each pixel of at least one column on the image sensor and comparing the signal waveform with a preset signal waveform of a finger of a living body The personal authentication method using subcutaneous blood flow measurement according to any one of claims 1 to 4, wherein One or two irradiation means for spreading the laser beam to irradiate the finger pad, a light receiving means for receiving reflected light from a blood vessel layer under the finger pad, having a large number of pixels, and obtained by the light receiving means Storage means for storing the output of each pixel, calculation means for calculating the amount of temporal change in the amount of received light in each pixel from the storage contents of the storage means, and calculation results obtained in each pixel A second storage means for storing the two-dimensional distribution of the blood flow as a blood flow map, and a means for comparing and determining the blood flow map stored in the second storage means with pre-registered personal data In the authentication apparatus, the irradiation means and the light receiving means are arranged so that a laser irradiation site and an observation area of reflected light by the image sensor are shifted from each other, and a personal authentication apparatus using subcutaneous blood flow measurement, . Means for detecting a simulated finger by detecting a signal waveform representing the intensity distribution of the amount of received light in each pixel of at least one column on the image sensor, and comparing the signal waveform with a preset signal waveform of a biological finger The personal authentication device using subcutaneous blood flow measurement according to claim 6, wherein: The laser beam is spread to irradiate the finger pad, and the light reflected from the subcutaneous blood vessel layer is imaged as a laser speckle on the image sensor using an optical system, and the amount of light received by each pixel of the laser speckle An amount representing the speed of change is calculated, the numerical value is converted into a two-dimensional map to obtain a blood flow map of the finger pad, the blood flow map is compared with collated personal data, Laser irradiation in a personal authentication method using subcutaneous blood flow measurement, characterized in that a change in the average blood flow over time or in a certain region is obtained over time, and the obtained value is compared with a predetermined standard. A personal authentication method using subcutaneous blood flow measurement, in which a laser speckle is imaged on an image sensor using an area shifted from a region as an observation area of the image sensor. One or two irradiation means for spreading the laser beam to irradiate the finger pad, a light receiving means for receiving reflected light from a blood vessel layer under the finger pad, having a large number of pixels, and obtained by the light receiving means Storage means for storing the output of each pixel, calculation means for calculating the amount of temporal change in the amount of received light in each pixel from the storage contents of the storage means, and calculation results obtained in each pixel A second storage means for storing the two-dimensional distribution as a blood flow map, and means for comparing and determining the blood flow map stored in the second storage means with pre-registered personal data In the personal authentication device comprising means for calculating the change over time of the average blood flow in the whole or in a certain region and comparing / determining the obtained value with a predetermined reference, the irradiation means and the light receiving means , Laser irradiation site and image Personal authentication device using subcutaneous blood flow measurement, characterized in that it is arranged so that the observation area of the reflected light is shifted by capacitors. Means for detecting a simulated finger by detecting a signal waveform representing the intensity distribution of the amount of received light in each pixel of at least one column on the image sensor, and comparing the signal waveform with a preset signal waveform of a biological finger The personal authentication device using subcutaneous blood flow measurement according to claim 9, wherein: The laser beam is spread to irradiate the finger pad, and the light reflected from the subcutaneous blood vessel layer is imaged as a laser speckle on the image sensor using an optical system, and the amount of light received by each pixel of the laser speckle An amount representing the speed of change is calculated, the numerical value is converted into a two-dimensional map, a blood flow map of the finger pad is obtained, and the blood flow map is compared with collated personal data. In the personal authentication method using the characteristic subcutaneous blood flow measurement, the intensity distribution of the amount of received light in each pixel for at least one column on the image sensor is expressed using the time zone before, after, or during the operation. A personal authentication method using subcutaneous blood flow measurement, characterized in that a signal waveform is detected and a function of detecting a simulated finger is added by comparing the signal waveform with a preset signal waveform of a biological finger. One or two irradiation means for spreading the laser beam to irradiate the finger pad, a light receiving means for receiving reflected light from a blood vessel layer under the finger pad, having a large number of pixels, and obtained by the light receiving means Storage means for storing the output of each pixel, calculation means for calculating the amount of temporal change in the amount of received light in each pixel from the storage contents of the storage means, and calculation results obtained in each pixel A second storage means for storing the two-dimensional distribution of the blood flow as a blood flow map, and a means for comparing and determining the blood flow map stored in the second storage means with pre-registered personal data In the authentication device, a signal waveform representing the intensity distribution of the amount of received light in each pixel for at least one column on the image sensor is detected, and the signal waveform is compared with a preset signal waveform of a biological finger to simulate a simulated finger. Added a means to detect Personal authentication device using subcutaneous blood flow measurement, characterized and. The laser beam is spread to irradiate the finger pad, and the light reflected from the subcutaneous blood vessel layer is imaged as a laser speckle on the image sensor using an optical system, and the amount of light received by each pixel of the laser speckle An amount representing the speed of change is calculated, a finger blood flow map is obtained using the numerical value as a two-dimensional map, and the blood flow map is compared with collated personal data. In a personal authentication method using subcutaneous blood flow measurement, a laser beam is passed through a shielding plate having a number of horizontally long slits to project a lattice laser spot on the finger pad, and the scanning line of the spot and sensor Align the direction of the spot and analyze the data on the spot to detect the blood flow map on the surface of the finger pad and its change over time, or analyze the data between the spot and the finger Personal authentication method utilizing subcutaneous blood flow measurements and detecting a blood flow map of the inner portion and its change with time. The laser beam is spread to irradiate the finger pad, and the light reflected from the subcutaneous blood vessel layer is imaged as a laser speckle on the image sensor using an optical system, and the amount of light received by each pixel of the laser speckle The amount representing the speed of change is calculated, and the blood flow map of the finger pad is obtained using the numerical value as a two-dimensional map, and the blood flow map is compared or collated with personal data registered in advance, or all or there is In a personal authentication method using subcutaneous blood flow measurement, in which an average blood flow in a region is obtained over time, and the obtained value is compared and determined with a predetermined standard, laser is A grid-like laser spot is projected onto the finger pad by passing through a shielding plate having a slit, and the spot and the scanning line direction of the sensor are aligned, and the data on the spot is analyzed. The blood flow map of the surface layer of the finger pad and its change over time are detected, or the data between the spots is analyzed to detect the blood flow map of the inner layer of the finger pad and its change over time. A personal authentication method using subcutaneous blood flow measurement.

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